Big Delta is a census-designated place (CDP) in Southeast Fairbanks Census Area, Alaska, United States. The population was 591 at the 2010 census, down from 749 in 2000. Big Delta is at the confluence of the Delta River and the Tanana River and gets its name from the huge river delta formed by the confluence.

Southeast Fairbanks Census Area is a census area located in the U.S. state of Alaska. As of the 2020 census, the population was 6,808, down from 7,029 in 2010. It is part of the unorganized borough and therefore has no borough seat. Its largest communities are Deltana and Tok, both unincorporated CDPs.